Haunting Masticore

At the beginning of your end step, sacrifice
Haunting Masticore unless you discard a card.
{3}: Haunting Masticore deals 1 damage to target creature or planeswalker.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its
owner control with a +1/+1 counter on it.)